Development Kit
2.2 Serial RS232 Interface
The RS232 level serial interface is implemented with a transceiver that converts from the
XPort™ 3.3V CMOS levels to RS-232 levels. A straight-through serial cable with 9-pin
connectors (M/F) is all that is required to connect to a DTE device such as a PC.
The table below lists the RS232 Signals. Note that XPort™ signal pins 6, 7, and 8 are
configurable pins and can be set for functions other than RS-232 control. A configuration
DIP switch determines if the XPort™ configurable pins are routed to the RS-232 converter.
Table 5 - RS232 Signals
XPort™ Signal
XPort™ Pin
Direction
DB-9 Pin #
DCD
pin 7 configured as
DCD
Out 1
Data Out
pin 4
Out
2
Data In
pin 5
In
3
DTR
pin 8 configured as
DTR
In 4
Ground pin
1
5
RTS
pin 8 configured as
RTS
In 7
CTS
pin 6 configured as
CTS
Out 8
2.3 RS232 Port
The Evaluation Board uses a Maxim MAX3238 IC to convert all RS232 interface signals to
3.3V CMOS level XPort™ signals.
The MAX3238 IC was selected because of it capability of true RS232 level performance
from a +3.3V input power source and for its 15kV ESD protection. The part also includes a
RS232 valid output that is used to light an LED via the PLD circuit.
2.4 Power Supply
The Evaluation Board contains a +3.3V regulator that receives input power via a 2.5mm
input power jack. The input power should be 5VDC from a regulated DC source. A +5VDC
power module is provided with the evaluation kit.
It is recommended that the evaluation board should also be connected to an earth ground. It
can be connected to earth ground via the chassis ground rectangle (copper tape), TP7, or
the shell of the DB9 connector.
2.5 General Control PLD
The purpose of the PLD is to provide general Evaluation Board mode control and LED
signal level monitoring. The PLD works in conjunction with the 6-position mode control
switch (SW1) and the Timer and Reset circuits to provide mode control.
The PLD is a Lattice ISPLSI2032VE part, which is contained in a 48-pin TQFP package.
This part contains 32 I/O and 32 microcells and is in-circuit programmable. A 1x8-pin header
(JP3) is also provided for standard Lattice in-circuit programming.
XPort™ User Manual and Development Kit
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